fix(z10): skip enter-state write for noreturn syscalls

After p10 suppressed the sys_exit_exit/sys_exit_exit_group handlers, the
enter handlers for exit/exit_group still called ior_on_syscall_enter,
which writes a per-tid entry into syscall_enter_state_map. With the exit
handler gone, nothing ever bpf_map_delete_elem'd that entry, so stale
per-tid state accumulated in the bounded (32768) map on hosts churning
many distinct tids and could starve legitimate inserts.

Add ior_on_noreturn_syscall_enter in internal/c/filter.c: it only makes
the sampling decision (ior_should_emit_trace) and deliberately does NOT
record enter-state. The code generator now emits this hook for noreturn
enter handlers (detected via isNoreturnSyscall(syscallName(name))) so the
enter null_event is still emitted while the dead, unreclaimable map write
is skipped. Regenerated generated_tracepoints.c accordingly.

Extend TestGenerateExitNoreturnHandlers with a negative assertion (no
ior_on_syscall_enter for noreturn) and add
TestGenerateReturningSyscallEnterRecordsState as a positive contrast.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

0 files changed, 0 insertions, 0 deletions